The present invention relates to web material (e.g., fibrous web material) for absorbing odorous substances, methods for forming such material and saturant slurry compositions used for making such material. The invention is also directed to personal care products (such as sanitary napkins, tampons, diapers and incontinence pads) containing web material for absorbing odorous substances; and sterilized sealed packages containing medical materials (such as hospital gowns), wherein offensive odors upon opening the sealed packages are avoided.
Sequestration of undesired odorous substances in a non-volatile form, by adsorption or absorption on a sorbent, is a known technique. One means for providing such sequestration is to incorporate particles of a material for absorbing odorous substances (hereinafter also odor-absorbing particulate material) in a sheet-like body; the odorous substances are absorbed by the particles of sorbent material, so as to sequester the undesired odorous substances.
It has been desired to provide odor-absorbing fibrous web material (that is, fibrous sheet material for absorbing odorous substances), having odor-absorbing particulate incorporated in a fibrous base web, the web material being non-dusting (that is, wherein particulate material in the web material does not fall out after manufacture of the odor-absorbing web material). It is desired to provide odor-absorbing web material which has good odor-absorbing properties and is non-dusting, yet which can easily and inexpensively be manufactured.
Various odor-absorbing web (e.g., sheet) materials have previously been disclosed. For example, U.S. Pat. No. 2,690,415 discloses an odor-absorbing, flexible, sheet-like body which may be used in the capacity of a bandage, dressing, blanket or the like to absorb odors emanating from, for example, glandular excretions, wherein the sheet-like body contains one or more layers of granular odor-absorbing material uniformly dispersed throughout the body and secured therein (against displacement) by means of a permanently pliable adhesive. This patent discloses use of a web of open-mesh flexible woven material such as is commonly referred to as surgical gauze, the web being of open-mesh construction provided by relatively wide spacing between individual weft and warp strands, and is provided in the regions wherein the weft and warp strands overlap one another with discrete particles or masses of a permanently pliable adhesive. This patent also discloses that an exemplary adhesive includes a water-emulsion asphaltic-type of adhesive, or one of the synthetic resinous or latex base adhesives using solvents or plasticizers that may be easily evaporated or driven-off by heat treatment of the adhesive after application to the gauze web. This patent further discloses that after application of the adhesive, the odor-absorbing material in its granular form may be sprayed or sprinkled upon the adhesive-containing areas of the gauze web on one or both sides thereof, or the adhesive-containing web may be passed through a mass of the granular material to cause adherence between the individual granules of odor-absorbing material and the discrete particles of adhesive.
U.S. Pat. No. 4,289,513 discloses sorption paper (a relatively dense, non-porous paper as compared to filter paper) for absorbing odors associated with, for example, body waste devices such as sanitary napkins and disposable diapers, wherein a fibrous base paper material, which is resiliently flexible, is loaded with activated sorption particles. In its specific use for absorbing odors of body waste, the sorption paper is inserted in the sanitary napkin or diaper, to remove the odors. The sorption sheet material disclosed in U.S. Pat. No. 4,289,513 includes a fibrous base paper material which is resiliently flexible, with activated sorption particles dispersed in the fibrous base material, such particles being substantially uniformly dispersed throughout all dimensions of the fibrous base material, in an amount up to about 85% based on the weight of the base material. However, this patent does not disclose how the particles are uniformly dispersed throughout all dimensions of the fibrous base material. This patent discloses that there is a substantial absence of loose, dusty sorption particles due to use of a particular binder material, such binder material being a latex-type binder, preferably an anion polymeric emulsion of latex material (the latex materials including polyvinyl chloride copolymer, acrylics, vinylidene chlorides, acrylonitriles, vinyl acetates, polybutadiene, styrene butadiene, phenolic resins and combinations thereof). This patent further discloses that the sorption particles can include activated carbon, activated silica gel, polymeric absorbent materials, molecular sieves, ion exchange resins and other carbonaceous absorbent materials.
U.S. Pat. No. 4,525,410 discloses a fiber article having anti-bacterial properties, which article retains zeolitic particles having a bactericidal activity in fibers having fused intersection points. This patent discloses that the zeolite particles are capable of contacting with external fluids through cavities in the fibers, and that the fiber article is composed of a mixed fiber assembly including (1) natural fiber staples or synthetic fiber staples, and (2) fiber staples containing low-melting thermoplastic synthetic fibers having a melting point at least 30.degree. C. lower than the melting point or the decomposition point of the aforesaid natural fiber staples or synthetic fiber staples. This patent discloses that at least a part of the intersection points of the staples of the mixed fiber assembly have the intersecting fibers stuck to each other by the fusion of the low-melting thermoplastic synthetic fibers. The zeolitic particles are incorporated in the fiber body by having the zeolitic solid particles contact the mixed fiber assembly while the low-melting thermoplastic synthetic fibers are in a molten state, with pressure then being applied and then the mixed fiber assembly being cooled to fix the particles onto the mixed fiber assembly.
U.S Pat. No. 4,748,065 discloses a spun-laced fabric having incorporated therein adsorbent carbonized particles, the particles being distributed over the entire fabric and dispersed throughout the cross-section of the fabric, but with more of the particles being located near the surface of the fabric, with the particles being held in place by an organic binder. This patent discloses that the fabric incorporating the adsorbent carbonized particles can be produced by brush-coating a base spun-laced fabric, on each side, with a mixture of aqueous slurries containing an aqueous slurry of activated carbon absorbent particles and an aqueous slurry of a synthetic copolymeric latex (including a polymer of ethyl acrylate and poly(vinylidine chloride/methyl acrylate/itaconic acid)).
While each of the foregoing patents describes various sheet materials for removing odors and/or noxious materials, it is desired to provide a more satisfactory odor-absorbent sheet material. In particular, it is desired to provide a more satisfactory web material that is both non-dusting and effectively removes odors, yet which can be manufactured inexpensively. It is also desired to provide such web material, which has a clean, unobtrusive appearance. It is further desired to provide such web material, which has applications in many different fields where odors arise (e.g., in refrigerators, or other enclosed spaces where there is poor exchange of fresh air).
In the previously discussed U.S. Pat. No. 4,289,513, specific applications for use of sorption paper to absorb odors are disclosed. One of the applications disclosed therein is to absorb odors emanating from devices for absorbing body liquid wastes, such as catamenial devices. Such odor can be caused by the following materials in body wastes, or formed from body wastes, absorbed in catamenial devices: (1) triethylamine; (2) pyridine; (3) furaldehyde; (4) isovaleric acid; and (5) n-propyl sulfide.
As a further area where odor is a problem, in the gamma-sterilization of medical materials (for example, hospital gowns made from polypropylene fibers) in a sealed package, an unfortunate and highly aggravating side effect of the irradiation sterilization of the polypropylene materials is that a highly offensive odor is present upon opening of the package.
Thus, in manufacturing such medical material packages, initially the medical material is made and subjected to various treatments, such as to make the materials alcohol-repellent and lint-free. The materials are then packed into a package, with the package then being sealed. Thereafter, the sealed package is subjected to gamma-irradiation sterilization, to sterilize the medical material. However, the gamma sterilization causes malodorous materials to form in the sealed package, so that when the package is opened a highly offensive odor is present. Accordingly, it is also desired to avoid the offensive odors present upon opening of the medical material-containing packages.
Thus, it is desired to provide catamenial devices, such as sanitary napkins and tampons, wherein odors emanating from such devices, due to liquid body wastes absorbed in such catamenial devices, are avoided. It is also desired to provide sealed sterilized packages, containing medical (for example, surgical) materials illustrated by hospital gowns, wherein offensive odors upon opening the sterilized packages are avoided. It is further desired to provide sterilized medical packages and catamenial devices, wherein odors emanating therefrom are avoided, while dusting of odor-absorbing particulate material (on, for example, the surgical material) is avoided. It is also desired to avoid such odors by a technique that can be provided inexpensively yet effectively, and yet which has a clean and unobtrusive appearance.
While the above-discussed documents may disclose products, processes and apparatus which exhibit some of the characteristics of the present invention, none of them discloses or suggests the present invention (including the advantages thereof), which achieves the objectives as discussed below.